The present invention relates to fuel caps for closing filler necks of vehicle fuel tanks. More particularly, the present invention relates to a threaded fuel cap that provides a lost motion driving connection between a handle and a closure member to delay actuation of the closure member in a cap-removal direction.
Conventional fuel caps for closing threaded filler necks of vehicle fuel tanks generally include an outer handle or shell that is coupled for rotation to a closure member or housing. The housing is normally formed to include threads that are configured to engage corresponding threads formed on the filler neck. It is known to provide a torque override driving connection between the handle and housing to prevent overtightening of the housing within the filler neck during installation of the cap on the filler neck. For example, U.S. Pat. No. 4,280,346 to Evans shows a torque-override cap. It is also known to provide either a direct driving connection or delayed actuation driving connection between the handle and the housing. For example, U.S. Pat. No. 4,765,505 to Harris shows a delayed actuation driving connection fuel cap.
It would be advantageous to provide a fuel cap with a delayed actuation drive connection that includes a minimum number of parts. The cost of manufacturing is reduced and ease of assembly is increased by providing a cap using a minimum number of parts to create a delayed actuation driving connection feature in the cap.
According to the present invention, a cap is provided for use in a filler neck. The cap includes a closure or housing for closing the filler neck and a handle for rotating the closure relative to the filler neck. The cap also includes a delayed action device for providing a lost motion driving connection between the handle and closure. The delayed actuation device includes an annular torque transmission ring engaged with the closure and a driven lug appended to the annular torque transmission ring. The delayed actuation device also includes a drive pin integrally appended to the handle and arranged to engage the driven lug during rotation of the handle about its axis of rotation.
One feature of a cap in accordance with the present invention is that the cap provides a delayed actuation driving connection and includes a minimum number of parts. The handle is illustratively formed to include a drive pin thereon during the manufacturing process so that it is not necessary to provide a separate part having a drive pin and then mount that separate part to the handle during assembly of the cap. This reduces the cost and complexity of manufacturing fuel caps outfitted with delayed actuation driving connections.
In preferred embodiments of the present invention, the delayed actuation device includes a pair of drive pins integrally appended to a downwardly facing wall of the handle and a pair of driven lugs appended to the annular torque transmission ring. Each driven lug is arranged to extend in a radially inward direction toward the axis of rotation of the annular torque transmission ring. The pair of drive pins and pair of driven lugs are arranged relative to one another so that one of the drive pins engages one of the driven lugs during rotation of the handle relative to the filler neck in either a cap advancing direction or a cap removal direction.
Illustratively, the handle is a unitary piece made of molded plastics material. Conveniently, the two drive pins integrally appended to the handle are the integrally formed ejector pins provided on the handle and used in the molding process to manufacture the handle. This further minimizes the cost and complexity of manufacturing by using an existing fuel cap handle mold and cleverly cutting the ejector pins to a predetermined length and configuring driven lugs appended to the annular race so that the shortened ejector pins and the specially constructed driven lugs cooperate to generate a lost motion driving connection between the handle and the cap housing.
Also in preferred embodiments of the present invention, the pair of drive pins and pair of driven lugs are spaced apart to provide a lost motion driving connection between the cap and the filler neck. The lost motion is defined by the distance a drive pin travels once it disengages a first driven lug in one direction until it engages the second driven lug in an opposite direction. One of the driven lugs is L-shaped to define pocket means for holding and releasably retaining one of the drive pins when the cap is moved to its filler neck-closing position.
Advantageously, the L-shaped driven lug retains one of the drive pins to prevent any of the lost motion from being lost due to cap-drifting. This ensures the delayed actuation driving connection will exist when the cap is in its closed position on the filler neck. The other driven lug is arranged to assist in establishing a driving connection between the handle and the cap housing.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.